Method of printing pharmaceutical forms and product thereof



, thereon.

United States Pat ent METHOD OF PRINTING PHARMACEUTICAL FORMS ANDPRODUCT THEREOF Edward M. Heifer-nan, Levittown, N.J., and Allan M. Rad,Elkins Park, Pa, assignors to Smith Kline & French Laboratories,Philadelphia, Pa, a. corporation of Pennsylvania No Drawing. Filed Feb.11, 1963, Ser. No. 257,792

' (Ilaims. (Cl. 16'782) This invention relates to a novel method ofprinting on pharmaceutical forms such as tablets, pills and the like andthe product of this method. More particularly, this invention provides aversatile, simplified method of printing on pharmaceutical forms whichgreatly reduces the time previously required.

The technique of the prior art involved in the ink monogramming oftablets has been to apply a preprintiug coat of ink receptive material,preferably shellac, over the coated tablets and printing the desired inkindicia The present method of applying the shellac to the pharmaceuticalforms is very time consuming. The coated tablets, in particular sugarcoated tablets, must be thoroughly dried before the application of theshellac coat in order to prevent frosting of the shellac by the presenceof moisture. The present method con sists of applying the desired tabletcoating, removing the tablets from the coating pan after the final colorcoats have been applied and then drying the tablets overnight. Thetablets after being completely dried are then placed in a specialshellacking pan and one or more coats of wax free shellac are appliedout of a suitable organic solvent, usually isopropyl alcohol. Since thisshellac is incompatible with water it is absolutely necessary that thetablets have been thoroughly dried before the application of theshellac. The time required to assure complete drying is approximately 24hours. The shellac coated tablets are then removed from the coating pan,monogrammed and polished.

The novel method of printing tablets and the tablet in accordance withthis invention eliminates the above time consuming procedure and makesit possible to print tablets rapidly and inexpensively. The timerequired to print the tablets has been'reduced from days to a matter ofhours. The novel process of printing tablets as disclosed by theapplicants eliminates the necessity of tablets being dried overnightbefore the application of the shellac. Another advantage of this novelinvention is that less handling of the tablets is required since they donot have to be racked and repanned a second time. A further advantage ofthis invention is that it permits for a preprinting coating of thepharmaceutical forms in the same pan in which they are sugar coatedfollowing the normal pan drying cycle thus eliminating the necessity ofspecial shellacking pans. The method and tablet of this invention, istherefore, markedly less expensive than those disclosed in the prior artbecause of the great reduction in operating time and the elimination ofspecial shellac coating pans discussed above.

The method of printing the solid pharmaceutical forms such as compressedtablets, pills, troches and the like in accordance with this inventioncomprises preparing a preprinting coating solution of a solid cellulosederivative in an organic solvent in which the derivative is sufficientlysoluble. The cellulose coating solution is then applied directly to thepharmaceutical forms immediately after they have been given theirstandard coating and printed and polished. This method provides for acon ice tinuous operation in the coating pan starting with the coatingof the medicinal core to the final cellulose coatmg.

The cellulose coating solution is prepared by dissolving a solidcellulose derivative in an organic solvent in a concentration of fromabout 1% to about 10%, preferably from about 2% to about 5%. The solidcellulose derivative can be any nontoxic, water insoluble, cellulosesuch as, for example, ethyl cellulose, propyl cellulose, celluloseacetate or cellulose acetate butyrate. The process of this invention iscarried out most advantageously by the use of ethyl cellulose.

In accordance with this invention the organic solvent is any nontoxicpharmaceutically acceptable volatile solvent in which the cellulosederivative is soluble. Exemplary of such solvents would be chloroform,carbon tetrachloride, petroleum ether, benzene, trichloroethylene,ethylene dichloride, alcohols, such as, methyl, ethyl and isopropyl ormixtures of the above solvents.

The advantageous and preferred preprinting coating solution inaccordance with this invention will contain from about 2% to about 5% ofethyl cellulose in chloro form. The coating will be from about 0.01% toabout 0.1%, preferably from about 0.01% to about 0.05% of the totaltablet Weight.

The printing and polishing of tablets referred to above are very wellknown conventional steps in the tableting art. For example, the printingcan be accomplished simply by biasing the tablets against a printingmechanism such as a stamp or roller having the desired monagram andsaturated with any of the well known edible inks. Tablet printingmachines are available to perform a continuous operation of printing andconveying the tablets, i.e., mass production.

The polishing operation is well known to the art and the materials usedmay be, for example, beeswax, carnauba was, ozokerite or ceresin.Preferably a combination of beeswax and carnauba wax in variousproportions is used.

The coated tablets referred to in this invention can have any coatingwell known to the art, such as for example, sugar coating, entericcoating, film coating or the many different forms of sustained releasecoatings.

The solid pharmaceutical forms which are printed using this novelprocedure comprises coated tablets, pills,

' troches and the like substantially and completely coated with acellulosic material and having an ink identifying monogram marked upon aportion of the cellulose coating. If desired, the tablet can be'finishedwith a polishing coat of wax.

While this invention applies mainly to the pharmaceutical industry it isto be understood that this method of printing can be applied to anyindustry which desires to ink monogram their'edible products.

It will also be apparent to those skilled in the pharmaceutical art thatmethods of coating equivalent to those described hereinbefore could beused, such as, for ex-.

ample, using air suspension, fluid bed or press coating methods.

The following example is not limiting but rather illustr-ative of themethod of this invention.

Example Ingredients: I Amounts, gm. Ethyl cellulose, N.F., 15 cps. 3.0Chloroform 97.0

A preprinting coating solution is prepared by dissolving the ethylcellulose in the chloroform. Tablet cores containing chlorpromazine andfiller are placed in a rotating coating pan and are sugar coated anddried. While continuing to rotate the coating pan the ethyl cellulosesolution coated tablets in the rotating pan and allowed to dry. Thetablets are then removed from the coating pan and ink monogrammed. thenapplied to the printed tablets. 5

i) is then applied to the sugar A polish coating of beeswax is What isclaimed is: 1. A method of preparing printed pharmaceutical forms whichcomprises:

(a) Applying a standard coating composition to pharmaceutical formsrotating in a coating pan to give coated forms,

(b) Drying said coated forms,

(0) Covering said coated forms rotating in a coating pan With acellulosic preprinting coating solution to give cellulose coatedpharmaceutical forms, and

(d) Ink printing said cellulose coated pharmaceutical forms.

2. The method of claim 1 characterized in that the standard coatingcomposition is a sugar coating.

3. The method of claim 1 characterized in that the preprintingcellulosic coating solution comprises ethyl cellulose.

4. The method of claim 1 further characterized in that the ink printedpharmaceutical forms are finished with a polishing coat of wax.

5. An link monogrammed pharmaceutical form comprising a coated medicinalcore, an ethyl cellulose preprinting coat surrounding said coated coreand ink monogramming on a portion of said preprinting coating.

References Cited in the file of this patent UNITED STATES PATENTS2,853,420 Lowey Sept. 23, 1958 3,080,294 Shepard Mar. 5, 1963 3,116,205Heilig et al Dec. 31, 1963

1. A METHOD OF PREPARING PRINTED PHARMACEUTICAL FORMS WHICH COMPRISES:(A) APPLYING A STANDARD COATING COMPOSITION TO PHARMACEUTICAL FORMSROTATING IN A COATING PAN TO GIVE COATED FORMS, (B) DRYING SAID COATEDFORMS, (C) COVERING SAID COATED ROTATING IN A COATING PAN WITH ACELLULOSIC PREPRINTING COATING SOLUTION TO GIVE CELLULOSE COATEDPHARMACETUICAL FORMS, AND (D) INK PRINTING SAID CELLULOSE COATEDPHARMACEUTICAL FORMS.